The present invention relates generally to an apparatus for operating elevator shaft doors and, in particular, to an apparatus for the coupling, unlatching and entraining of elevator shaft doors actuated by the door drive on the elevator car.
Collapsible and splayable entraining member parallelogram linkages are a conventionally used technique in elevators for the coupling, unlatching and entraining of shaft doors. An entraining mechanism based on this principle and an unlatching device connected therewith are shown in the European patent application no. 0 410 774. A parallelogram linkage fastened at the car door is splayed and collapsed in the known
In the collapsed state of the above described equipment, the shaft door rollers are not touched during travel of the elevator car past floors. On arrival of the car at a stopping floor, the parallelogram linkage is splayed, the shaft door rollers are urged laterally apart the shaft door is thereby coupled and unlatched for entrainment during opening and closing of the car door.
Equipment of this type basically fulfills its intended purpose. However, the entraining rollers must be arranged in exact vertical alignment at the shaft doors for all floors which requires corresponding adjustment operations during the elevator installation. The lateral spring travel of the cars in high performance elevators, which is grater for the purpose of vibration damping, moreover demands a reduction in the opening speed of the entraining member during the coupling of the car door and the shaft door in order to limit the noise development connected therewith.